Investigation was undertaken to study the effect of vitamin E and Se on clinical and sub clinical mastitis in military dairy farm Mhow and in and around Indore district. Efficacy of Vitamin E and Se on occurrence of sub clinical and clinical mastitis was evaluated on the basis of Clinical parameter, Somatic Cell Count and California mastitis test results. The patient history, physical examination, marking on slide, recording of data remained the most crucial steps during complete study of work.